YUSHI YUT-28 Series User manual

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Contents
CHAPTER 1 A BRIEF INTRODUCTION TO YUT-28SERIES................................................................... 1
1.1 NAMES OF THE MAJOR COMPONENTS OF THE INSTRUMENT....................................................................1
1.2 KEYPAD.....................................................................................................................................................1
1.3 DISPLAY SCREEN.......................................................................................................................................2
1.4 BASIC OPERATION OF THE INSTRUMENT.................................................................................................. 2
1.4.1 Power Supply................................................................................................................................................. 2
1.4.2 Probe Connection........................................................................................................................................... 3
1.4.3 Switching On and Off the Instrument............................................................................................................ 3
1.4.4 Restore the Initial Parameters of the Instrument............................................................................................3
1.5 MAIN MENU AND FUNCTIONS.................................................................................................................. 3
1.5.1 Functional Keys ............................................................................................................................................3
1.5.2 Main Menu ................................................................................................................................................... 4
CHAPTER 2 FUNCTIONS, FEATURES, AND PARAMETERS OF THE INSTRUMENT.....................4
2.1 BASIC FUNCTIONS OF THE INSTRUMENT................................................................................................... 4
2.2 FEATURES OF THE INSTRUMENT................................................................................................................5
2.3 SPECIFICATIONS........................................................................................................................................ 6
CHAPTER 3 DETAILED OPERATION INSTRUCTIONS......................................................................... 6
3.1 PARAMETER MENU FUNCTIONS................................................................................................................ 6
3.1.1 Sound Path..................................................................................................................................................... 6
3.1.2 Sound Velocity............................................................................................................................................... 7
3.1.3 Displacement..................................................................................................................................................7
3.1.4 Gain................................................................................................................................................................ 7
3.1.5 Compensation.................................................................................................................................................8
3.1.6 Scale............................................................................................................................................................... 8
3.1.7 Reject..............................................................................................................................................................8
3.1.8 Wave Height Readings................................................................................................................................... 8
3.2 SETTING MENU.........................................................................................................................................9
3.2.1 Waveform Filling........................................................................................................................................... 9
3.2.2 Color Scheme................................................................................................................................................. 9
3.2.3 Language........................................................................................................................................................ 9
3.2.4 Alarming.........................................................................................................................................................9
3.2.5 Automatic Wave Height................................................................................................................................. 9
3.2.6 Date.............................................................................................................................................................. 10
3.2.7 Time..............................................................................................................................................................10
3.2.8 Parameter Resetting......................................................................................................................................10
3.3 SQUARED WAVE MENU............................................................................................................................ 10
3.3.1 Pulse energy................................................................................................................................................. 10
3.3.2 Pulse width................................................................................................................................................... 11
3.3.3 Damping....................................................................................................................................................... 11
3.3.4 Broadband.................................................................................................................................................... 11
3.3.5 Repeating frequency.....................................................................................................................................11
3.4 GATE MENU............................................................................................................................................... 12

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3.4.1 Gate A menu.................................................................................................................................................12
3.4.1.1 Starting of gate A.......................................................................................................................................12
3.4.1.2 Width of gate A......................................................................................................................................... 12
3.4.1.3 Height of gate A........................................................................................................................................ 12
3.4.1.4 Mode of gate A..........................................................................................................................................13
3.4.1.5 Display choice...........................................................................................................................................13
3.4.2 Gate B menu ...............................................................................................................................................13
3.4.2.1 Starting of gate B.......................................................................................................................................13
3.4.2.2 Width of gate B......................................................................................................................................... 14
3.4.2.3 Height of gate B........................................................................................................................................ 14
3.4.2.4 Mode of gate B..........................................................................................................................................14
3.4.2.5 Measuring point.........................................................................................................................................14
3.5 PROBE MENU...........................................................................................................................................15
3.5.1 Dual probes.................................................................................................................................................. 15
3.5.2 Probe zero.....................................................................................................................................................15
3.5.3 Probe K value...............................................................................................................................................15
3.5.4 Front distance............................................................................................................................................... 15
3.5.5 Work piece thickness....................................................................................................................................16
3.5.6 Probe type.....................................................................................................................................................16
3.5.7 Probe frequency............................................................................................................................................16
3.5.8 Probe diameter..............................................................................................................................................16
3.6 DAC MENU............................................................................................................................................ 17
3.6.1 DAC echo.....................................................................................................................................................17
3.6.2 Gate A start...................................................................................................................................................17
3.6.3 Distance compensation.................................................................................................................................17
3.6.4 DAC curve mode..........................................................................................................................................18
3.6.5 RL.................................................................................................................................................................18
3.6.6 SL................................................................................................................................................................. 18
3.6.7 EL.................................................................................................................................................................18
3.7 AVG MENU............................................................................................................................................... 18
3.7.1 AVG mode.................................................................................................................................................... 18
3.7.2 Gate Astart....................................................................................................................................................19
3.7.3 Sensitivity.....................................................................................................................................................19
3.7.4 AVG curve.................................................................................................................................................... 19
3.7.5 φ value calculation....................................................................................................................................... 19
3.8 MEMORY MENU.................................................................................................................................................... 19
3.8.1 Memory number...........................................................................................................................................19
3.8.2 Call-out.........................................................................................................................................................20
3.8.3 Storage..........................................................................................................................................................20
3.8.4 Deletion........................................................................................................................................................ 20
3.8.5 Communication............................................................................................................................................ 20
3.9 OPERATION OF OTHER SPECIAL FUNCTIONAL KEYS................................................................................. 20
3.9.1 Automatic gain............................................................................................................................................. 20
3.9.2 Freezing........................................................................................................................................................21
3.9.3 Wave peak memory...................................................................................................................................... 21
3.9.4 Full screen.................................................................................................................................................... 22

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CHAPTER 4 APPLICATION OF TESTING............................................................................................. 22
4.1 CALIBRATION METHOD AND STEPS OF THE INSTRUMENT......................................................................22
4.2 ZERO CALIBRATION OF THE STRAIGHT BEAM PROBE............................................................................ 22
4.2.1 Calibration Procedures................................................................................................................................. 23
4.2.2 Operation Steps............................................................................................................................................ 23
4.2.3 Measurement of the Sound Velocity of the Material....................................................................................24
4.3 CALIBRATION OF THE ANGLE BEAM PROBE...........................................................................................25
4.3.1 Calibration Procedures................................................................................................................................. 25
4.3.2 Operation Steps............................................................................................................................................ 25
4.4 MAKING OF DAC CURVE.......................................................................................................................... 27
4.5 MAKING OF AVG CURVE...........................................................................................................................28
CHAPTER 5 SKILLS OF USING THE INSTRUMENT.............................................................................29
5.1 FLEXIBLE USAGE OF THE GATE.............................................................................................................. 29
5.2 MAKING THE BEST OF THE PROMPTING MESSAGES ON THE SCREEN DRUING THE OPERATION PROCESS 30
5.3 SAVING AND CALLING THE INSTRUMENT STATUS AND THE DETECTION PARAMETERS............................30
5.4 USING BATTERIES TO REDUCE INTERFERENCE........................................................................................ 30
5.5 SWITCHING THE DISPLAY MODES............................................................................................................ 30
5.6 PEAK VALUE MEMORY FUNCTION........................................................................................................... 31
CHAPTER 6 APPLICATION AND PRACTICE OF FLAW DECTETION..............................................31
6.1 APPLICATION ON STEEL PLATE FLAW DETECTION....................................................................................31
6.1.1 The adjustment of testing scope................................................................................................................... 31
6.1.2 The adjustment of sensitivity....................................................................................................................... 32
6.1.3 the identification of flaws.............................................................................................................................32
6.1.4 Flaw Evaluation............................................................................................................................................32
6.1.5 Flaw Quantify...............................................................................................................................................32
6.1.6 The identification of the defect location...................................................................................................... 33
6.2 THE APPLICATION ON THE WELDING LINE FLAW DETECTION.....................................................................33
6.2.1 Operating steps.............................................................................................................................................34
6.2.2 Measurement of the flaw length...................................................................................................................34
CHAPTER 7 MAINTENANCE AND REPAIRING.....................................................................................35
7.1 OPERATORS’ TRAINING........................................................................................................................... 35
7.2 INSTRUMENT MAINTENANCE...................................................................................................................35
7.3 ENVIRONMENT REQUIREMENTS.............................................................................................................. 35
7.4 MAINTENANCE OF RECHARGEABLE BATTERY........................................................................................... 36
7.5 BATTERIES REPLACEMENT........................................................................................................................ 36
7.6 MAINETANCE............................................................................................................................................ 36
CHAPTER 8 COMMUNICATION BETWEEN THE INSTRUMENT AND THE COMPUTER..........37
8.1 THE COMMUNICATION BETWEEN YUT-28SERIES AND THE COMPUTER AND THE USE OF DATA
PROCESSING SOFTWARE.................................................................................................................37
8.2 MAIN FUNCTIONS..................................................................................................................................... 38
APPENDIX I FLAW DETECTION REPORTS........................................................................................... 39
APPENDIX II TERMINOLOGY................................................................................................................... 40

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Chapter 1 A Brief Introduction to YUT-28series
1.1 Names of the Major Components of the Instrument
Figure 1-1
1.2 Keypad
The keypad plays a role of mediator in the dialogue between human and machine. The keypad is
printed in Chinese and the layout of the keypad is shown in Figure 1-2. All the control instructions given
by the user to the flaw detector are finished entirely by the keypad. With the process of the keypad
operation, the instrument is able to identify various meanings of each key according to different
conditions and then to carry out the instructions of the operator. The detailed usage of each key will be
introduced respectively in the following chapters.
1. TFT True Color Display
2. Touch Keypad
3. D Ring
4. Hand Strap
5. Rotatable Stand
6. Power Adapter Port
7. Communication Port
8. T/R Probe Cable Port
9. R Probe Cable Port
The names of the major components of the instrument
are shown in Figure 1-1.
Figure 1-2

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1.3 Display Screen
Press to power the instrument on (the probe is not connected), and the screen is shown as
Figure 1-3.
1.4 Basic Operation of the Instrument
During the operation of the instrument, directly press the corresponding menu key, and the relevant
menu will be displayed on the screen. There are 6 main menus in YUT-28series; and each main menu
consists of several sub-menus, which can be switched through up and down keys among the operation
pages. The selected menu is highlighted; and its value can be adjusted through left and right keys.
1.4.1 Power Supply
Using AC Adapter
Alternating current can be used to power YUT-28series through an AC adapter. Plug the power
output terminal of the AC adapter into the socket on the YUT-28series.
Using Batteries
A pack of exclusive rechargeable built-in batteries can be used in YUT-28series, as shown in Figure
1-4.
Figure 1-3
Figure 1-4

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1.4.2 Probe Connection
When you use YUT-28series, we recommend using our stock probe connecting cable with the
appropriate probes. Various types of our standard stock probes can be used directly.
The probe should be plugged into the socket upside the instrument. When it is the mode of single
probe, the probe cable should be connected to T/R socket; when it is the mode of dual probe (one for
transmitting, the other for receiving), you should plug the transmitting probe into the T/R socket and the
receiving probe into the R socket. If these factors are not paid attention to, unfavorable results might be
loss or disordered echo waveform.
1.4.3 Switching On and Off the Instrument
Press to directly start up YUT-28series and activate the standby mode. After the detection and
data storage, press for two seconds
to shut down the instrument.
1.4.4 Restore the Initial Parameters of the Instrument
If the instrument crashes or some functions are in disorder or the parameters of the instrument need
resetting, press twice then press (up) key or (do) key to select the submenu resetting
parameters. Then press (left) key or (right) key to adjust the parameters. When the screen
displays resetting parameters confirmation, press Ok to restore the parameters.
Note: after the instrument is initialized, all the parameters are reset to the factory defaults.
1.5 Main Menu and Functions
1.5.1 Functional Keys
Automatic gain
Increase or decrease the highest wave inside the gate to 80% of the
screen
Freezing
Waveform freezing
Wave Peak Memory
Automatically store the highest wave
Full screen
Full screen display
On/off
Switch on and off
Menu control keys
Up, down, left, right
and OK
Up/down keys are used to switch among options, left/right keys are
used to adjust values.

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1.5.2Main Menu
Main
Menu
Submenu
Functions
Basic
Gain, Compensation, Sound Velocity, Sound Path, Displacement,
Scale, Reject, Wave Height Readings
Basic Parameters
in Detection
Setting
Waveform Filling, Color Scheme, Language, Alarm, Automatic
Wave Height, Date, Time, Parameter Resetting,
Basic Functions of
the Instrument
Gate
Gate A Start, Gate A Width, Gate A Height, Gate A Mode, Display
Mode, Gate B Start, Gate B Width, Gate B Height, Gate B Mode,
Measurement Point
Relevant Options
Setting Gate
Probe
Dual Probes, Probe Zero, Probe K Value, Front Edge Length, Work
Piece Thickness, Probe type, Probe frequency, Probe diameter
Relevant Options
Setting Probe
Curve
DAC Echo, Gate A Start Position, TVG, Curve mode, RL, SL, EL;
AVG mode(YUT-2820), Sensitivity, Aperture, AVG curve, Φ value
Setting of Making
DAC/AVG Curve
Storage
Memory Number, Call Out, Storage, Deletion, Communication
Setting of Data
Storage
Squared
wave
Pulse Energy, Pulse Width, Damping, Broadband, Repeating
Frequency
Match the probe
perfectly
Chapter 2 Functions, features, and parameters of the instrument
2.1 Basic functions of the instrument
Wave peak memory: real time envelopes show the highest wave of the flaws and record the
maximum value of the flaws, it is helpful to position the flaws precisely and scan the work piece quickly.
With the help of envelope waveform, the quality of the flaws can be determined.
Automatic gain: automatically adjust the gain to the preset amplitude height
Alarming function: afferent echo/echo loss alarming
Real-time clock: automatically record and store the date and time of waveforms
Display freezing: catch waveforms and sound path data at any moment, and the gate can be moved
after freezing to measure the echo parameters
Flaw positioning: real-time display sound path S, horizontal X, depth Y, and wave height H
Digital Reject: 0-80%, increase by 1%, unaffecting the linearity and gain
Wave height reading: three display modes, namely relative wave height, dB difference relative to
the gate, and dB difference relative to DAC curve
Data communication: communicate with the computer through RS232 port to transmit waveforms
and data so as to manage the result of detection on the computer, and generate the flaw detection reports,
as well as print out reports

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2 independent measurement gates, monitoring the echo amplitude and the sound path distance
When using transverse wave to detect flaws, the depths of the second and third waves are
automatically calculated according to the slab thickness.
Perfect DAC/AVG curve functions, the curves change along with the changes of the gain, sound
path, and displacement.
2.2 Features of the instrument
The firm and durable instrument shell is specially designed for the hostile site environment.
31 copper screw nuts are inlaid in the hard plastic casing
Innovative rotating positioning bracket is easy to use.
The hand strap can be installed for both hands so that you can hold the machine with your left
or right hand.
The D-shaped ring on the instrument is convenient for installing a cheststrap.
The corrosive texture of the shell surface is scratch-resistant and beautiful.
Innovative high power lithium batteries of notebook style.
Full screen function, the echo display area can cover the entire screen, which provide you with the
sense of the maximum window
Solid waveform displays, the visual contrast of waveforms is increased so the undetection is hard
to happen when fast scan is carried out
Bulk storage, up to 1000 data sets can be stored, including waveforms, curves, and parameters
(containing the traditional 1000 channels)
Echo-echo thickness measurement, zero calibration is avoided, and the net thickness of the base
material can be directly measured through the coating
Squared ultrasonic pulse generator with changeable width and scope is initiative domestically.
It replaces the traditional method of matching probe by changing damping with adjusting the pulse
energy and pulse width. Thus, the probe can be exactly fit for the testing and the resolution and
penetrating power of the approaching surface can be enhanced significantly. It is specially fit for the
testing of large scale of forge piece, casting piece and non-metal with the requirement of higher
penetrating power and lower electric noise.
●The voltage of the pulse generator can be changed between 50V to 400V continuously, so that no
matter thin plate or hard-penetrated work-piece can be matched with the most fitful probe.
●The width of the pulse can be changed between 25ns to 1000ns continuously, so that the best
sensitivity can be realized with the help of different probes with different frequency.
Damping can be changed among 4 levels: 33/50/100/500Ω, so that the best performance of the
probe can be attained and the different requirements of the sensitivity and resolution can be realized.

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Wave signal filter can be changed between 2 levels: 1-4MHz/0.5-15MHz. Each individual
advantage of narrowband and broadband filter can be achieved.
Repeating frequency can be changed freely to avoid unreal signal.
Two operation interfaces are available, i.e., Chinese and English
Easy to use, the user can master the operation method very fast.
2.3 Specifications
Working frequency: (0.5-15) MHz
Detection coverage: (0-4500) mm
Sound Velocity of the Material: (1000-9999) m/s
Operation mode: pulse echo, dual crystal
Pulse displacement: (0-2000) mm
Probe zero: (0-99.99) µs
Damp: 33/50/100/500Ω
Gain adjustment: (0-110)dB，0.1dB、1.0dB、2.0dB、6.0dB Full automatic adjustment of steps
Reject scope: 0-80% adjustable
Vertical linearity error: ≤3%
Horizontal linearity error: ≤0.3%
Resolution: ＞40dB(5P14)
Dynamic range: ≥32dB
Sensitivity allowance: ≥55dB （200mm deep Φ2 Flat-bottom hole)
Data storage: 1000 data sets, including flaw detection status parameters, echoes, DAC curves
Average electric noise and level: ≤10%
Battery types: high power lithium battery
Standby time of the batteries: 9 hours
External dimension: 270mmX190mmX60mm
Weight: 1.5kg without batteries
Chapter 3 Detailed Operation Instructions
3.1 Parameter Menu Functions
Press to start the menu.
3.1.1 Sound Path
On the sound path submenu, you can make the adjustment of the display range, i.e., the frequency of
the echo displayed. The range is from 25 to 4500mm.
On the parameter menu, press (up) or (down) to select the sound path submenu, then

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press (left decrease) or (right increase) to adjust the values.
On the sound path submenu, press OK to adjust the steps. The steps are 1, 10, 25, and 100.
3.1.2 Sound Velocity
On the sound path submenu, you can adjust the velocity of the ultrasonic wave transmitted in the
detected work piece. The range of adjustment is from 1000 to 9999m/s.
On the parameter menu, press (up) or (down) to select the sound velocity submenu,
then press (left decrease) or (right increase) to adjust the values.
On the sound velocity submenu, press Ok to adjust the steps. The steps are 1, 10, 100 and V-V.
When V-V is selected, you can switch between two preset velocities, namely 5920m/s or 3240m/s.
The Sound Velocities of Some General Materials
Materials
Transverse
Sound
Velocity
Longitudinal
Sound
Velocity
Materials
Transverse
Sound
Velocity
Longitudinal
Sound
Velocity
Copper
2260m/s
4700m/s
Organic Glass
1460m/s
2730m/s
Aluminum
3080m/s
6300m/s
Steel
3230m/s
5920m/s
Iron
3230m/s
5900m/s
Epoxy Resin
1100m/s
2500m/s
3.1.3 Displacement
The displacement submenu displays the starting point of the screen. When the value is adjusted, the
waveform will move horizontally. The adjustment range is from 0 to 2000mm.
On the parameter menu, press (up) or (down) to select the displacement submenu, then
press (left decrease) or （right increase) to adjust the values.
On the displacement submenu, press OK to adjust the steps. The steps are 1, 10, 25, and 100.
3.1.4 Gain
The gain submenu enables you to adjust the sensitivity of the instrument. Its unit is dB. The higher
is the gain, the more sensitive the instrument is, and vise versa. The adjustment range is from 0 to
110dB.
On the parameter menu, press (up) or (down) to select the gain submenu, then press
(left decrease) or (right increase) to adjust the values.
On the gain submenu, press Ok to adjust the steps. The steps are 0.1, 1.0, 2.0 and 6.0.

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3.1.5 Compensation
Owing to the different degrees of roughness of surface of the detected object and the test block
calibrating the instrument, in the practical detection, you need to increase (or decrease) the sensitivity of
instrument to reduce the influence caused by the surface of the detected object. The range of adjustment
is from -40 to +40 dB. The values used in the adjustment are related to the gain values.
On the parameter menu, press (up) or (down) to select the compensation submenu,
then press (left decrease) or (right increase) to adjust the values.
On the compensation submenu, press Ok to adjust the steps. The steps are 0.1, 1.0, 2.0 and
6.0.
3.1.6 Scale
This function enables you to adjust the display mode of the screen coordinate.
On the parameter menu, press to activate the function. Press (up) or (down) to
select the scale submenu, then press (left) or (right) to switch among various display
modes.
S Sound Path: the actual distance of the sound wave from the surface of the work piece to the flaw.
X Horizontal Distance: the horizontal distance of the sound wave from the point of incidence to the
flaw.
Y Vertical Distance: the vertical distance of the sound wave from the surface of the work piece to
the flaw.
3.1.7 Reject
After you adjust to a value, the echo below the value can be cleaned. For instance, you can remove
the structural noise of the detected work piece. The reject setting is shown by % on the screen, and the
adjustment range is 0-80%.
On the parameter menu, press to activate the function. Press (up) or (down)
to select the reject submenu, then press (left) or (right) to adjust the values.
You should handle this function with great caution, as it may happen that you suppress echoes from
flaws as well. In addition, some specifications expressly forbid using the reject function.
3.1.8 Wave Height Readings
Ha% The percentage of the waveform accounting for of the screen height in windows.
dBa The dB difference of the waveform relative gate can be shown in windows. When you use

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this function, you should use Gate A to catch the echoes. Otherwise, it will result in error in reading.
SL In the windows, the dB difference of the quantitative line relative to DAC curve will be
shown. If there is no DAC curve, then it displays SL ----.
Hint: on the parameter menu, the 8 submenus are shown on two screens - the former five ones on
one screen, and the latter three ones on the other screen. You can switch among them by pressing .
3.2 Setting Menu
Press to select the setting menu.
3.2.1 Waveform Filling
This function enables you to adjust the waveform displaying mode.
Select the setting menu, press (up) or (down) to select the waveform filling submenu,
then press (left) or (right) to select off or on. Off refers to enveloping, and On refers to
filling.
3.2.2 Color Scheme
You can use the function to adjust the colors on the screen.
Select the setting menu, then press (up) or (down) to select the color scheme
submenu. Then press (left) or (right) to choose one of seven color schemes.
3.2.3 Language
You can use this function to choose a language.
Select the setting menu, the press (up) or (down) to select the language submenu. Then
press (left) or (right) to choose Chinese or English.
3.2.4 Alarming
You can use this function to set whether there is an alarm.
On the setting menu, press to activate the function. Press (up) or (down) to
select the alarming submenu. Then press (left) or (right) to set the alarm. Off refers to
turning off the alarm, while on refers to turning on the alarm.
3.2.5 Automatic Wave Height
You can use this function to set the percentage of the height of the automatic gain waveform on the

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screen. The default status is 80%.
Select the setting menu, press (up) or (down) to select the automatic wave height
submenu. Then press (left) or (right) to adjust the values. The maximum value is 80%,
while the minimum is 20%.
3.2.6 Date
On the setting menu, press to activate this function. Press (up) or (down) to
select the date submenu. Then press (left) or (right) to set the date.
Press Ok to switch among year, month, and day.
3.2.7 Time
On the setting menu, press to activate this function. Press (up) or (down)
to select the time submenu. Then press (left) or (right) to set the time.
Press Ok to switch among hour, minute, and second.
3.2.8 Parameter Resetting
Select the setting menu, press (up) or (down) to select the parameter resetting submenu.
Press (left) or (right) to choose whether to reset the parameters, and press Ok to
reset the factory defaults. If you want to cancel the resetting, press any key.
In the setting menu, 10 submenus are displayed on two screens, the former five ones on one screen
and the latter five ones on the other. You can switch among them by pressing ..
3.3 Squared Wave Menu
Press to select the SQU menu.
3.3.1 Pulse Energy
Through adjusting the value, the sensitivity and resolution of the echo can be changed. With higher
pulse voltage, the instrument shows higher sensitivity, wider pulse and weaker resolution. With lower
voltage, the situation is inversed.
On the squared ultrasonic wave menu, press (up) or (down) to select the Pulse-EN
submenu, then press (left decrease) or (right increase) to adjust the values. The maximum
value is 400V, and the minimum value is 50V.

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3.3.2 Pulse width
Through adjusting the value, the sensitivity and resolution of the echo can be changed. This
function aims at matching different probes and getting the highest sensitivity.
On the squared ultrasonic wave menu, press (up) or (down) to select the Pulse-W
submenu, then press (left decrease) or (right increase) to adjust the values. The maximum
value is 1000ns, and the minimum value is 25ns.
The pulse width and pulse frequency can be changed in turn by pressing (left decrease) or
(right increase).The pulse frequency can be adjusted between 0.5MHz to 20MHz. The pulse frequency
should be as similar as that of the probe center.
3.3.3 Damping
To adjust the damping of the oscillating circuit, and thereby to change the width, height and
resolution of the echo display, the damping can be adjusted.
On the squared ultrasonic wave menu, press (up) or (down) to select the damping
submenu, then press (left decrease) or (right increase) to adjust the values. There are 4
levels for option. The maximum value is 500Ω, and the minimum value is 33Ω.
With higher damping value, the echo is wider and higher. With lower damping value, the echo
is narrower and lower, but usually with higher resolution.
3.3.4 Broadband
The broadband function is to adjust the frequency of the ultrasonic wave when testing.
On the squared ultrasonic wave menu, press (up) or (down) to select the broadband
submenu, then press (left decrease) or (right increase) to turn the values: 0.4-15MHz or
1.0-4.0MHz.
3.3.5 Repeating frequency
The repeating frequency function is to set the detective times within the original pulse.
On the squared ultrasonic wave menu, press (up) or (down) to select the Repetition
Frequency submenu, then press (left decrease) or (right increase) to adjust the values: 25Hz,
50Hz, 100Hz and 200Hz.

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3.4 Gate Menu
The most outstanding feature of the digital flaw detector is the ability to display all the analogue
values of echoes on the screen by digital signals. When the instrument is required to compare and
compute a signal wave, "human" is needed to tell it which echo to trace. We appoint "gate" for locking
the echo to be measured. The instrument handles and computes the echo inside the gate as well as
displays all the data of the highest echo (including data of the sound path, the horizontal distance, the
vertical distance, and the height).
The instrument works in a dual-gate mode with Gate A and Gate B. The reading mode of the gate is
single gate one. The user can choose Gate A as the current gate. Next, we are going to introduce the
adjustment of the position, width, and height of the gate based on the current gate.
Press to activate the gate menu. Press it for odd times to select Gate A, even times to select
Gate B.
3.4.1 Gate A Menu
3.4.1.1 Starting of Gate A
Press for odd times to select the Gate A menu, then press (up) or (down) to
select the starting of Gate A submenu. Then press (left) or (right) to adjust the values.
Note: the starting of Gate A is the forward position of Gate A. The adjustment range: 0-9998mm.
When you adjust the values, you can press Ok to adjust the steps which are divided into 1, 5, and 10.
3.4.1.2 Width of Gate A
Select Gate A menu, press (up) or (down) to select the width of Gate A submenu, then
press (left) or (right) to adjust the values.
Note: the width of Gate A is the backward position of Gate A. Minimum adjustment range is 2mm,
while the maximum one is same as the sound path value. When you adjust the values, you can press Ok
to adjust the steps which are divided into 1, 5, and 10.
3.4.1.3 Height of Gate A
Select Gate A menu, press (up) or (down) to select the height of Gate A submenu, then
press (left) or (right) to adjust the values.
Note: the height of Gate A is the response and measurement thresholds. You can adjust the value in
the 2%-98% range of the vertical full-scale on the screen. When you adjust the values, you can press Ok
to adjust the steps which are divided into 0.5, 2.5, and 5.

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3.4.1.4 Mode of Gate A
Select Gate A menu, press (up) or (down) to select the mode of Gate A submenu, then
press (left) or (right) to adjust the values.
Off Turning off the gate, i.e., turning off the alarming and measurement functions.
Positive Afferent Echo Alarm. In the coverage of Gate A, if the echo exceeds the preset gate
height, and the alarm is "on", the alarm will sound.
Negative Echo Loss Alarm. In the coverage of Gate A, if the echo is lower than the preset gate
height, and the alarm is "on", the alarm will sound.
3.4.1.5 Display Choice
Select Gate A menu, press (up) or (down) to select the display choice submenu, then
press (left) or (right) to adjust the values.
Note: when the function is off, the screen is closed. The other data is shown at the top right corner
of the screen.
Display
Meaning
Display
Meaning
Sa
The sound path value of the echo in Gate
A
Ha
The height of the echo in Gate A
Sb
The sound path value of the echo in Gate
B
Hb
The height of the echo in Gate B
ba
The path difference of the echoes in Gate
A and B
Da
The vertical distance from the surface
of the work piece to the flaw echo in
Gate A
Ra
The projection distance from the probe
front edge to the flaw echo in Gate A.
Db
The vertical distance from the surface
of the work piece to the flaw echo in
Gate B
Rb
The projection distance from the probe
front edge to the flaw echo in Gate B
dBa
The dB difference from the echopeak
in Gate A to the gate level position
off
Close display
dBb
The dB difference from the echopeak
in Gate B to the gate level position
3.4.2 Gate B Menu
3.4.2.1 Starting of Gate B
Press for even times to select the Gate B menu, then press (up) or (down) to
select the starting of Gate B submenu. Then press (left) or (right) to adjust the values.
Note: the starting of Gate B is the forward position of Gate B. The adjustment range: 0-9998mm.
When you adjust the values, you can press Ok to adjust the steps which are divided into 1, 5, and 10.

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3.4.2.2 Width of Gate B
Select Gate B menu, press (up) or (down) to select the width of Gate B submenu,
then press (left) or (right) to adjust the values.
Note: the width of Gate B is the backward position of Gate B. Minimum adjustment range is 2mm,
while the maximum one is same as the sound path value. When you adjust the values, you can press Ok
to adjust the steps which are divided into 1, 5, and 10.
3.4.2.3 Height of Gate B
Select Gate B menu, press (up) or (down) to select the height of Gate B submenu,
then press (left) or (right) to adjust the values.
Note: the height of Gate B is the response and measurement thresholds. You can adjust the value in
the 2%-98% range of the vertical full-scale on the screen. When you adjust the values, you can press Ok
to adjust the steps which are divided into 0.5, 2.5, and 5.
3.4.2.4 Mode of Gate B
Select Gate B menu, press (up) or (down) to select the mode of Gate B submenu, then
press (left) or (right) to adjust the values.
Off Turning off the gate, i.e., turning off the alarming and measurement functions.
Positive Afferent Echo Alarm. In the coverage of Gate B, if the echo exceeds the preset gate
height, and the alarm is "on", the alarm will sound.
Negative Echo Loss Alarm. In the coverage of Gate B, if the echo is lower than the preset gate
height, and the alarm is "on", the alarm will sound.
3.4.2.5 Measuring Point
You can use this function to set the measuring point position of the gate.
Select the Gate B menu, press (up) or (down) to select the measuring point
submenu. Then press (left) or (right) to choose the values. The peak mode refers to the
highest information of the echo in the gate, and the front mode refers to the first information when the
echo goes through the gate.
Note: in the peak mode, the echo need not go through the gate; while in the front mode, the echo
must go through the gate.

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3.5 Probe Menu
Press to select the probe menu.
3.5.1 Dual Probes
You can use this function to set the probe types.
Select the probe menu, press (up) or (down) to select the dual probes submenu. Then
press (left) or (right) to adjust the values.
Note: On refers to the dual probes mode; while Off refers to the single crystal probe mode.
3.5.2 Probe Zero
There is a certain sound path distance between the probe chip and the coupling surface of the work
piece to be detected, thus there will be a sonic time delay. The delay effect can be compensated by
setting the probe zero submenus.
Select the probe menu, press (up) or (down) to select the probe zero submenu. Then
press (left) or (right) to adjust the values.
Note: the adjustment range is 0-99.99μs. In the adjustment, you can press Ok to adjust the steps,
which are divided into 0.01, 0.1, and 1.
3.5.3 Probe K Value
When the angle beam probe is used, the included angle value (β) between the sound beam in the
work piece of the incidence of the sound wave and the surface normal should be set as: K value - k=tg
β.
Select the probe menu, press (up) or (down) to select the probe K value submenu.
Then press (left) or (right) to select the probe K value and the probe angle. Press (up)
or (down) to select the value option, then press (left) or (right) to adjust the value.
Note: when you adjust the probe K value, press Ok to adjust the steps of the K value. When you
adjust the probe angle, press Ok, then you are able to adjust the steps of the probe angle head. The steps
of the K value are 0.01, 0.1, and 1. The adjustment range is 0-9.99. The steps of the angle are 0.1, 1, and
10. The adjustment range is 0-89.9.
3.5.4 Front Distance
In the menu, you can set the front edge length value of the probe (referring the distance between the
front edges of the angle beam probe to the point of incidence of the probe).

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Select the probe menu, press （up) or (down) to select the front distance submenu.
Then press (left) or (right) to adjust the values.
Note: the adjustment range: 0-999.9mm. When you adjust the values, you can press Ok to set the
steps, which are divided into 0.1, 0.5, and 1.
3.5.5 Work Piece Thickness
On the work piece thickness submenu, you can set the work piece thickness in the vertical direction
of the detection plane. When using angle beam probe, the positioning of the vertical depth of the flaws
need this value set. The reason is that when non-primary reflection is used in the detection, if the work
piece thickness is not considered, it will result that the instrument might produce an outcome that the
vertical depth value is larger than the actual thickness of the work piece when it automatically measures
the vertical depth.
Select the probe menu, press (up) or (down) to select the work piece submenu. Then
press (left) or (right) to adjust the value.
Note: the adjustment range: 0-999.9mm. When you adjust the values, you can press Ok to set the
steps, which are divided into 0.1, 1, and 10.
3.5.6 Probe Type
In the probe type submenu, you can alter the probe type between straight beam probe and the
angle beam probe. This function is usually used when making AVG curve.
Select the probe menu twice, press (up) or (down) to select the probe type submenu.
Then press (left) or (right) to change the probe type.
3.5.7 Probe Frequency
This menu is used for choosing the frequency of the probe.
Select the probe menu twice, press (up) or (down) to select the probe frequency submenu.
Then press (left) or (right) to change the probe frequency.
When adjusting the values, you can press Ok to set the steps, which are divided into 0.01, 0.1, and 1
3.5.8 Probe Diameter
This menu is used for choosing the size of probes.
Select the probe menu twice, press (up) or (down) to select the probe diameter
submenu. Then press (left) or (right) to change the probe frequency.
The probe diameter option is relative to probe type: with straight beam probe, adjust the value
directly; with angle beam probe, adjust the width of the crystal and then press OK to adjust the length of
it.

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3.6 DAC Menu
Owing to the diffusion and attenuation of the sound velocity, the echo heights of the reflectors of
the same size depend on the distance between the reflector and the probe. The distance amplitude curve
is made according to different reference reflectors which are the same size but different in their depths,
and a curve diagram mode displays the influences and the changes. When the DAC curve is being made,
the material of the reference block with artificial flaws should be same as the work piece to be tested.
Note: When the DAC curve finished is activated, if you adjust some parameters, the prompt line
will display "a DAC curve has been made, the parameter is locked", if you really need to change the
parameter, you can close the DAC curve, and the DAC echo will be cleared. A new DAC curve will be
made after the adjustment.
Press to enter the DAC menu.
3.6.1 DAC Echo
Select the DAC menu, press (up) or (down) to select the DAC echo submenu. Then
press (left) or (right) to adjust the value.
Note: The functional option of the DAC echo is used to display the current number of the echo
reference points, the maximum quality is 9, and confirm the echo reference points.
3.6.2 Gate A Start
Select the DAC menu, press (up) or (down) to select the Gate A start submenu. Then
press (left) or (right) to adjust the value.
Note: adjust the Gate A position to catch the reference echo. The adjustment range is 0-9999mm.
3.6.3 Distance Compensation(YUT-2820)
When penetrating through the work-piece, the sonic power of ultrasonic waves always attenuates
along with the enlargement of the spreading distance. When detecting the flaws of large work-pieces and
severe attenuated materials, the high receiving sensibility is required to discover the small flaw signals.
However, with the ultra high sensitivity, the crystal interface refection and probe disordered echoes will
be high and the near field blind area is enlarged. To solve this problem, YUT-28series is designed for
distance compensation. When the resolving power in the near field is not influenced, only the remote
signal will be compensated for its sensitivity so as to improve the testing range of the device
significantly. Before using this function, DAC curve should be made first.
Select the DAC menu, press (up) or (down) to select the TVG submenu. Then
press (left) or (right) to adjust. When shows OFF, close Distance Compensation, and ON
turn on the Distance Compensation.